1956 10 Johnson shifting problem

[twocyclemania]

I've had this motor for years. Would work on it now and than. Would never stay in forward and probably reverse. As a winter project I would like to complete it. I runs beautifully engine-wise. I swapped out the lower unit with another (not sure of that one's condition but had it laying around so I thought I'd give it a try) but had the same problem. Is there anything in the upper part of the motor (shift handle/linkage,etc) that I should look at? Do I have to remove the powerhead. I'm really having my doubts that it's in the lower unit though this would not be the first time I'm wrong. Thanks for any advice!

 

[HighTrim]

Does it jump out of gear, mainly at higher RPMS? With a THUNK like you are hitting a log, or just slip out of gear randomly?

 

[twocyclemania]

It's been a while since I played with it. I'm not really sure which one it is. What are the ramifications of either? thanks!

 

[F_R]

If it actually comes out of gear, or goes thunk and continues on to repeat, the usual cause is worn out clutch dog and possibly forward gear in the lower unit. Related to that is worn out or battered shift linkage below the powerhead. Either problem can contribute to the other one.

However, if it only slips like spinning your wheels on the ice (smooth slip with no banging or noise), that probably is a spun propeller hub.

 

[oldboat1]

another thought --

Chance of both l.u.s producing the same problem might be a little improbable, seems to me. I wonder if you are incorrectly installing the shift rod connector. The two ends have to be fully inserted or the length of the rod is changed, potentially affecting operation.

If the problem started on the other l.u. after the gearcase was apart, that could be another clue (potential reassembly issue).

 

[twocyclemania]

I've had motors with a bad slip clutch in the prop and this is not it. It's not a smooth, as you go slippage. Haven't had either lower unit apart. Was hoping to swap out and go but the problem continues the same with either lower unit. Could be both units but suspicion is that it maybe something up inside the leg at the shift but I'm not too familiar with problems at that end. Would it be worth pulling the power head to take a look? thanks!

 

[HighTrim]

First, did you ensure the bolts that go through the holes for the shift rod connector are PERFECTLY aligned with the detent in the shift rod. Look through hole in connector with flashlight, before installing bolt, and ensure that the detent is lined up with hole.

Now, look at shift handle. Unlikely, but perhaps out of sync/setting. Shift, and rotate prop as you do to ensure it engages/disengages as it should.

Worn clutch dog on a 50s QD isn't all that unlikely. Very likely both gearcases have bad dogs. I would flip a motor, and pull the skeg to see. Can be inspected in a couple minutes.

 

[oldboat1]

don't mean to flog it, but I'm referring to the connector between the upper and lower shift shafts -- the brass connector with two screws or bolts. When you removed the lower units, you would have disconnected the shift rods. That connector could be the common issue. It's possible to connect one or both of the shafts without fully inserting them -- bolts have to go through the machined groove in the shaft ends.

[ed. as above....with addit. suggestions]

 

[F_R]

Actually, it is pretty easy to evaluate the upper linkage, and without pulling to powerhead to do it. Simply remove the inspection plate on the side and take a look, combined with some common sense. Obviously if the connector is not properly installed as suggested a few times, that would be an issue. Secondly, watch the rod as you move the shifter. When you move the handle, does the rod move up and down with no slop or delay? It should. Thirdly if you move the handle slowly while spinning the prop, does it "catch" forward and reverse equally in distance from neutral? It should. However, it might be expected to favor forward in case of slop in the linkage. But understand that is fixing the result rather than the cause. If you do these observations and everything appears to be acceptable, time to take a look at the clutch dog and gear. Wear-out of these parts is extremely common, almost to the point of being expected. That is just the real world. BTW, that is much less common on Mercs and Scots. Sorry 'bout that. Nevertheless, I prefer OMC.